Liverpool captain Gerrard, who came on shortly before half-time for Albert Riera, eventually drew the hosts level with a penalty 19 minutes from time although it looked as if David Ngog had dived to earn the spot-kick under pressure from Lee Carsley, the former Everton midfielder.
Although roared on by the crowd, Liverpool couldn't find a winner and the draw left under-pressure manager Rafael Benitez's side 11 points behind league leaders Chelsea.
Meanwhile Birmingham moved two points clear of the relegation zone.
Liverpool actually took an early lead through striker Ngog's close-range effort but rarely looked comfortable in the first half.
Christian Benitez headed in an equaliser before Cameron Jerome unleashed a stunning shot from some 35 yards to put Birmingham 2-1 up seconds before half-time.